The Relationship Between MRI-Based Paraspinal Fatty Degeneration, Bone Mineral Density and Sarcopenia Parameters in Postmenopausal Women

Objective: This study aimed to assess the relationship between lumbar paraspinal muscle fatty infiltration, sarcopenia parameters, BMD, and quality of life in postmenopausal women. Design: This cross-sectional study included 100 postmenopausal women aged 60–80 years. Sarcopenia was diagnosed according to the EWGSOP2 criteria. Lumbar MRI images were analyzed with ImageJ to determine muscle area, fat area, functional muscle area, and fat percentage, while fatty infiltration was graded using the Goutallier classification. Sarcopenia-related quality of life was assessed using the SarQoL. Results: Probable sarcopenia was identified in 77% of participants, while 29% met the criteria for confirmed sarcopenia and 13% for severe sarcopenia according to EWGSOP2. The sarcopenic group had significantly lower L1–L4 BMD ( P =0.016) and SarQoL scores (p≤0.034). Goutallier grades and ImageJ-derived paraspinal muscle parameters did not differ between sarcopenic and non-sarcopenic groups. Paraspinal fat area and fat ratio were negatively correlated with L1–L4 BMD and T-scores and positively correlated with the Goutallier index(all p≤0.009), whereas the mean functional muscle area showed the opposite relationship. No significant correlations were found with femoral-neck BMD. Conclusion: Although paraspinal muscle degeneration was associated with lumbar BMD and sarcopenia-related functional parameters, it may reflect region-specific musculoskeletal changes rather than a direct manifestation of systemic sarcopenia.